Methods for high-sensitivity detection and characterization of nucleic acid molecules are becoming increasingly important in many fields, such as diagnosis of diseases, early stage detection of a bacterial or viral infection, environmental monitoring, as well as fundamental biological research applications. Most sensitive DNA detection methods utilize the polymerase chain reaction (PCR) to amplify the target DNA sample to increase the concentration of target molecules prior to analysis. To determine the presence of a target DNA molecule, a fluorescently labeled oligonucleotide probe is often used to hybridize to the target DNA sequence and followed by the immobilization of the hybrids to a solid surface. Upon washing off the un-hybridized probes, the fluorescence signal is detected to confirm the presence of target DNA molecule. Alternatively, colormetric labeling can also be used as a means for signal generation. However, these methods are complicated, time-consuming and/or require the use of specialized and expensive equipment. A simple, fast method of detecting nucleic acids which does not require the use of such equipment would clearly be desirable.